Uranus Pathfinder
A proposed ESA–NASA orbiter for the Uranian system.
Uranus Pathfinder was a European Space Agency mission concept for the Uranian system, studied during the 2010s. The idea originated in 2011 from researchers at the UK’s Mullard Space Science Laboratory, who proposed a joint NASA–ESA medium-class (M-class) mission. It was submitted to ESA in 2011 with the backing of 120 scientists worldwide. M-class missions are capped at €470 million by ESA. The proposal supported ESA’s Cosmic Vision 2015–2025 program.
The mission study examined various launch dates, trajectories, and gravity-assist flybys—including Earth, Venus, and Saturn—noting that the velocity changes required were only slightly greater than those for typical Saturn missions of that era. The baseline design had a January 2025 launch on an Atlas V 551, using a Venus–Earth–Earth transfer to reach Uranus in November 2037 after a 12.8-year cruise. Once there, it would enter a highly eccentric, 45-day polar science orbit, with close periapsis passes to measure Uranus’s gravitational and magnetic fields with high precision.
The scientific payload, drawing heavily on European and international heritage, included a narrow-angle camera, visible/near-infrared imaging spectrometer, thermal infrared bolometer, radio science instrument, magnetometer, radio and plasma wave detector, and a plasma detector. During the long cruise, communication would rely on Earth stations at New Norcia (X band) and Cebreros (X and Ka bands). Several gravity-assist combinations were studied: VVE (Venus–Venus–Earth), VEE, EVVE, VEES (Venus–Earth–Earth–Saturn), and VVEES. For power, the proposal favored a European radioisotope thermoelectric generator using americium-241, with NASA’s MMRTG and ASRG as backup options offering more power.
- Proposed by
- Mullard Space Science Laboratory (UK)
- Agency
- European Space Agency (ESA) with NASA
- Mission class
- Medium-class (M-class)
- Proposed launch
- January 2025
- Proposed arrival
- November 2037
- Cost cap
- €470 million
- Key feature
- Highly eccentric 45-day polar science orbit
Lore & Background
In 2011, scientists from the Mullard Space Science Laboratory in the United Kingdom proposed the joint NASA–ESA Uranus Pathfinder mission to Uranus. It would have been a medium-class (M-class) mission to be launched in 2025, and was submitted to the ESA in 2011 with the signatures of 120 scientists from around the globe. ESA caps the cost of M-class missions at €470 million. Uranus Pathfinder was proposed in support of ESA's Cosmic Vision 2015–2025.
Reader's Guide
The mission study included several possible combinations of launch dates, trajectories, and flybys (gravity assists), including flybys of Earth, Venus, and of the planet Saturn. Indeed, the study noted the velocity change requirements are only marginally higher than for typical missions to Saturn of this period. In the baseline concept, UP is an ESA–NASA bilateral mission and it would launch on an Atlas V 551 in January 2025 on a Venus–Earth–Earth interplanetary transfer to Uranus, reaching Uranus orbit in November 2037 after a cruise phase lasting 12.8 years. It would orbit Uranus in a highly eccentric 45-day polar science orbit, with close periapsis distances to Uranus to make high-fidelity measurements of Uranus's gravitational and magnetic fields. The scientific payload has a strong heritage in Europe and beyond and includes: a narrow-angle camera, visible/near-IR imaging spectrometer, thermal IR bolometer, radio science, magnetometer, radio and plasma wave detector, and plasma detector. For power, the proposal suggests using a European radioisotope thermoelectric generator based on americium-241, with NASA's MMRTG and ASRG mentioned as possible backup options, which would provide more power.
Did You Know?
- The mission was proposed with signatures of 120 scientists from around the globe.
- The baseline launch vehicle was an Atlas V 551.
- The cruise phase to Uranus would have lasted 12.8 years.
- Possible gravity assists included flybys of Venus, Earth, and Saturn.
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